Centrifugal pump.



D. W. BLAIR.

OBNTBIFUGAL PUMP.

APPLICATION mum on 2, won.

Patented Nov. 22, 1910.

W X v. "m m u; o E .1 M flu n mmw M l 0 I H u. n m H 4| W I r m I v Iva k Ill J I M Ma -nhnw .u a! l l l m 9 8 M U N 2 u r a lmnvron 11am? Was/ 157110- ar y ' II I (HIE Y8 mums:

when subjected to the action of the ac d,

they are incapable of standing much-wear due to the rotation of the shaft. The collar 25"..btx-ausc of its material. is capable of withstanding considerable wear, even when subjected to the act ion of acid. I timl,tl-iero.i-v y usefore; that the collar- 25' is exceedin' fulin reducing the total amount of destruction taking place at this point in the mechanism. l lind. moreover, that as a rousequence .t can, by aid of the collar 25', so reduce the space between this collar audthe shaft 9 as to greatly cut down the tendency of air to enter between the cylinder and the shaft at times when otherwise there might be more or less tendency for the apparatus to induct such air. The reduced annular space around the shaft, rendered practicable by the use of the collar 25, also reduces the amount at energy lost or wanted in moving the liquid through this annular space, incidental to the circulation of the liquid, as elsewhere described.

ltemovably mounted in the casing to is a due 27 which constitutes a closure member. \hentlns plug is removed, the tank 22 is in tree communication with thecasing 15 through the hole normally occupied by the plug.

here acids, or other corrosive liquids, are to be pumped, the various parts exposed directl to the liquid should be made of acidproo material. stood, of course, that in handling acids and other corrosive llt aids, it is impracticable to maintain any t lt inary packing in a pum and it, iI-purtly upon this, account tint desire to form a liquid'packiug in the pump abovo dcserilmd.

The operation of my device is its-follows: The parts being assembled as indicated in Figs. 1 and 2. and the shaft 9 being turned by aid of the pullcv 10, the impeller .24, rotating'with the sha t, creates a artial vacuam in the middle portion of tie casing 15 and thereby causes the liquid 21 to travel upwardly through the supply pipe 19 and through the impeller 24 and casing 15, out.

into the discharge ipe 11: whereby it may lie-raised to a marsh crablo height. Suppose,

now, that the discharge pipe 16in quiteshort, and that the shaft. 9 isrunning at. a highfspeed. The li aid being thus acted upon quite energetica ly by the impeller, is forced violently outward through the dising a )wardl It will be undercharge iipe l6. The back pressure due to theheat ot" liquid in the discharge pi to bping quite small. the travel of all the iquid vin contact with the. impeller is outward through the slot 17-. It is'true that the back pressure of the liquid in the discharge pipe 16 has some tendency to force a portion of the liquid. up throu h the space between the sleeve Qa'rand the shaft 9, but this tendency is outweighed by the centrifugal motion of the li aid within, and in contact with, the hope ler. Hence, no liquid rises 'in the c lindrical sleeve 25. If, however, the

plug ll be now removed, a rtion of the iqutd in the casing 16 ma es its esca through the hole irevionsly occupied by this plug. The liquit tlrus esca ling )assesu wardly iato'the tank 22 Ill neary fills t le same, so as to cause an overtlow to take place through the overllow pipe 23. Since the level at the liquid in the tank 22 (being controllable by the position of the overflow pipe 23) is higher than theupper end of the sleeve 25, a )Olllflll of the li aid finds its way downward y between the 5 core 25 and the shaft t); The centrifugal motion of the impeller draws this portion of liquid downward and thus establishes and maintaihs continuously a circulation through the sleeve 25.. That is to say, liquid is constantly pusthrough the-hole normally occupict by he screw plug 27 and into the tank 22, thence downwardly through the sleeve .25 and below the bell-shaped portion 26 and slot 17 to the point whence it started. The shaft 9 is thus etlectively packed and sealed by a portionot the li id, and .to all intents and purposes is rendered air-tight in so far as the escape of liquid is concerned. Suppose, however, that the disehar 10 extends upwardly a considerable iatance, and that thehend of liquid contained in it is considerable. I n this event the rotary motion of the impeller is slower than usual owing to the superposed pressure of liquid in the discharge pipe l6. l'hc back pressure ot' -this liquid tends toforce a small portion of the liquid'up around the shaft 9, and it this pmsure exceeds a certain limit (which is varied by the speed of the impeller), the

liquid tends. notwithstandim, the ce'utrit'u gal force atl'ecting it. to ri e up around the slut ft 9 and to ovcrtlow from the top of the sleeve 25 In this event it is desira le to insert the plug 27, thereby cutting .olt direct couununication from thetauk 2 to the casing 15. This being done, the liquid now escapes from the top of the'slceve 35 and, nearly filling the tank .312, overllows through the pipevfil'il.

Under ideal conditions. the back pressure in the discharge pipe to may be so balanced relatively to the speed of rotation of the impeller 24, that a very small volume of liquid finds its way either upward or downward. as the case may be, around the Shaft. charged therefrom, said receptacle extending t and the waste of the liquid parking and to cause the same to seal. is negligible. .\s a general rule, the greater the speed of the im eller, the greater mav be the height of the discharge pipe 16. and consequently. the greater may be the pressure of the liquid discharged through this discharge pipe, the waste of ii uid through the sleeve .25 being lllttillltllllft at a minimum.

llavin; thus described my invention, I claim as new and desire to seem-e by Letters Patent: I

l. The combination of a casing provided with a e \'lindrieal member. an impeller revolnbly mounted within said tt|.-il|,'.!, a shaft tiltin" loosely into said cylindrical member uluii'onnerted with said hnpeller for the purm e of turning the latter. a lluid reeeptar e encircling said shaft and said rylindrieal member for the par so of storing a quantity of lluid disrlnlrget ing by aid of nmven-ents of said impeller, mul meansetmtrollable at will t'orgoverning the llow of said "aid from said easing into the-said receptacle in order to enable saul "aid to form a liquid seal between said rylindrieal member aml said shaft.

2. .In a centrifugal mmp, the combination of t t-using. an impeller mounted therein. a ahaft estemlilqz into said easing aml eonneeted with said impeller for turning the latter. a reee lltlt'lt' mounted upon said casing and adapted to hold a small quantity of liquid discharged from said casing while said pump is in action, said liquid thus stored eneu'elmg said shaft where it enters said pump, forming a liquid ,seal for preventing the lSt'llpt! of liquid arouml ttlllt shaft. aml an overllow pipe connected with said receptacle for removing excess of liquid contained within the same.

:2. The combination of a pum easing provided with an opening aml fart ier amended with a member of substantiallv cylindrical form, an impeller mounted within said casing and ada ued when in action to raise a liquid. aml aiso to diselnu'gu a small qmlntitv of said liquid through said opening. a sha t; lilting loosely into said substantially rvlindrieal member and eonueetml with Hllit impeller for the purpme of turnin" the latter, a receptacle mounted upon aaiirrusiug and connected .with said o :eniug l'nr the,pnr mse ot' rm-eiving from suit opening the lluid disl'rom said Hts-- power necessary to form upwardly to a greater altitude thalethe top v of .-aid member of substantially cylindrical form for guiding said liquid contained within said receptacle into the. space between said member of substantially cylindrical form aml said shaft in order to form a liquid Mlll.

l. The combination of a pump casing provided with an opening, a closure plu detaehably tittin mto said oienin an removable there rom at the wi l of tiite operator, a supply pipe and a dischar 'e pipe connected with sanl easing, an impel ermounted within said casing and adapted to receive a liquid from said supply pipeand to force the bulk of said liquid mto saiddischarge pipe a reeeptaele mounted upon said casing an adapted to receive therefrom a small quantity of liquid discharged through said opening. a shaft extending into said casing and connected with said impeller for the par pose of turning the latter, aml means for onabling said tuantity of liquid contained in said rece )tllt'lt! to form a liquid seal between said sha t and said easin 5. The combination 0 a casing provided with an opening and further provided with a substantially cylindrical portion, on impeller mounted within said caam a shaft extending through said cylindrica portion and con-- aeeted w ith said impeller for turn ng the latter, a discharge pipe, and a supply pipe conneeted with said casing. a receptacle disposed adjacent to said cylindrical direct. open communication with the interior of said casing, and means controllable at will for reversing the direction of travel of a li aid flowing between said shaft and said cylindrical portion.

0. The combination of a. casing, an impeller mounted therein, a receptacle dilpolod adjacent to said casing and in communication therewith by two paths, for the pn of permitting interchange of a liquid bo-' tween aaid cuin and said receptacle, and means eontrollab a at. will for closing one of said paths in order to reverse the direction of travel of said liquid.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

DAVID WESLEY BLAIR.

Witmms:

'AIItUN HARRISON, Plume 1.). Romauua.

rtion and in 

